Seismic surveying is used for identifying subterranean elements, such as hydrocarbon reservoirs, fresh water aquifers, gas injection reservoirs, and so forth. In performing seismic surveying, seismic sources are placed at various locations above an earth surface or sea floor, with the seismic sources activated to generate seismic waves directed into the subterranean structure. Examples of seismic sources include explosives, air guns, or other sources that generate seismic waves. In a marine seismic surveying operation, the seismic sources can be towed through water.
The seismic waves generated by a seismic source travel into the subterranean structure, with a portion of the seismic waves reflected back to the surface for receipt by seismic receivers (e.g., geophones, hydrophones, etc.). These seismic receivers produce signals that represent detected seismic waves. Signals from seismic receivers are processed to yield information about the content and characteristic of the subterranean structure.
It is often useful to know the positions of seismic receivers (and other components of survey equipment). Typically, in marine acquisition, the positions of the seismic receivers are determined using a high-frequency acoustic network. High-frequency sources in this network can emit signals that are recorded by the acoustic receivers. Note that such high-frequency sources used for positioning differ from seismic sources in that seismic sources usually operate in a lower frequency range. Note also that the acoustic receivers of the acoustic network can be the same as (or can be a subset of) the seismic receivers.
However, many conventional acoustic positioning techniques suffer from inaccuracies.